The present invention relates to a fluid supply apparatus in a shuttleless loom provided with a gripper which is arranged upstream of weft inserting means and operates in such a manner that the gripper releases a weft during the weft inserting operation and grips a weft from after the weft inserting operation to the start of next weft inserting operation.
In a shuttleless loom, because of the weft inserting mechanism for intermittently inserting the weft, in the side portion of the machine stand, there are ordinarily disposed a tensor for imparting a predetermined tension to the weft delivered out from a stationarily disposed weft feed zone, a weft storing zone for storing a predetermined quantity of the weft, a gripper arranged in the travelling course of the weft extended from the weft storing zone to weft inserting means and a cutter located on the end of a woven fabric to cut the weft at every weft inserting operation. However, heretofore there have been various problems which cause failures in the weft inserting operation in a shuttleless loom in connection with such an intermittent weft inserting operation. For example, in a shuttleless loom wherein a weft is temporarily reserved almost in a U-shaped form in a weft storing zone, a stored weft becomes entangled with itself and this will cause a failure in the weft inserting operation. That is, as illustrated in FIG. 1, in a conventional shuttleless loom if the loom is stopped because of erroneous weft inserting or yarn breakage during the operation, or if the loom is stopped out of necessity, while the loom is at a standstill, the loom is kept in the state ready for the weft inserting operation. Accordingly, the weft is kept in the U-shaped form on the storing plate 9. During this period of stoppage of the loom, however, the storing fluid jetting device 8 is working and the gripper 12 continues gripping the weft. Therefore, the weft Y.sub.1 on the delivery side of the storing plate 9 receives a tension of the fluid jetted from the storing fluid jetting device 8 and is kept stretched, but since the weft inserting operation is not performed, the weft Y.sub.2 on the take-out side receives no tension and is kept relaxed. Consequently, the weft Y.sub.2 is entangled with the weft Y.sub.1 on the delivery side by a strong return-twisting force to form an entangled portion Y.sub.3. The entanglement of the entangled portion Y.sub.3 is promoted by a turbulent flow caused by the fluid jetted from the storing fluid jetting device 8 because the weft Y.sub.2 on the take-out side is kept in the tension less state. When the loom is started again while entanglement is thus formed in the stored weft, the entangled or twisted portion Y.sub.3 is passed through the gripper 12 as it is and is brought to the weft inserting jet nozzle 16. Accordingly, the weft inserting jet nozzle 16 becomes clogged with the entangled portion of the weft and the weft inserting operation becomes impossible or an erroneous weft inserting occurs.
Even while the loom is being operated, since the gripper 12 is closed to grip the weft during the period of storing the weft after the weft inserting, the weft Y.sub.2 on the take-out side is kept in the tensionless state before a predetermined amount of the weft is stored, though the time during which the weft Y.sub.2 is kept in such free state is short. Accordingly, entanglement is often formed in the weft even while the loom is being operated.
Another problem which will cause a failure in the weft inserting operation is that fly wastes are generated and these fly wastes readily deposit on a tensor, a stored weft in the storing zone, a gripper and a cutter. For example, if fly wastes adhere to the tensor or gripper, the pressing force or gripping force on the weft is weakened, and it becomes impossible to impart a predetermined tension to the weft or to control the weft. Moreover, if a mass of fly wastes adheres to the weft, when a fluid jet nozzle is used for storing of the weft, this nozzle is readily clogged, and in the case of a jet loom, a weft inserting jet nozzle is similarly clogged, with the result that the weft storing operation or weft inserting operation cannot be performed.
As means for overcoming the disadvantage caused by fly wastes, there have heretofore been proposed a method in which a fluid is blown onto the gripper to remove fly wastes therefrom and a method in which fluid is jetted from the interior of the gripper in the radial direction toward the weft-gripping surface to remove fly wastes from the gripper, as disclosed in Japanese Patent Application Laid-Open Specification No. 78364/78, Japanese Utility Model Application Laid-Open Specifications No. 94870/76 and No. 94872/76. In these conventional techniques, however, since importance is attached only to removal of fly wastes, the weft inserting operation is more or less disturbed by the above-mentioned arrangement. More specifically, since the operation of removing fly wastes from the weft-gripping portion of the gripper is performed while the weft-gripping portion is opened to release the weft, that is, while the weft is advanced and the weft inserting operation is conducted, the weft is seriously influenced by the fluid jetted for removal of fly wastes and a large resistance is imposed on the weft inserting operation. Especially in the case of a jet loom, since the weft inserting operation is performed by the action of the fluid, erroneous weft inserting is readily caused by the influence of the fly waste-removing fluid on the weft.
Furthermore, if fly wastes deposited in the weft storing zone adhere to the weft, the fly wastes are carried to the subsequent gripper to weaken the gripping force of the gripper, and in the case of a jet loom, fly wastes not adhering to the gripper are further delivered to the weft inserting jet nozzle and this nozzle becomes clogged, with the result that the weft inserting operation becomes impossible. Since the cutter has to cut the weft at every weft inserting operation and it must be used very frequently with an accurate cutting capacity, if fly wastes are deposited on the cutter, the cutting function is degraded to render the weft inserting operation impossible.
Furthermore, in respective parts where removal of fly wastes is necessary, the removing operation must be performed at different timings. For example, the operation of removing fly wastes from the gripper should be performed while the gripper releases the weft. On the other hand, the operation of removing fly wastes from the weft storing zone should be performed during storing of the weft, that is, while the gripper grips the weft, because a large resistance is given to the weft if the fluid is jetted for removal of fly wastes during the weft inserting operation. Therefore, operations of removing fly wastes from the respective parts should be performed at different timings which are determined in such a manner that they are dependent on the respective functions.